ABSTRACT
Monthly samples of eight species of echinoids from the San Blas Islands, Panama were injected with isotonic Potassium Chloride solution to test their readiness to spawn. The percentage of animals that responded to these injections each month was used as an index of the reproductive activity of the populations. The samples revealed annual cycles in the reproduction of Echinometra viridis, Lytechinus williamsi, Clypeaster rosaceus, and Leodia sexiesperforata. These species are reproductively active during Panama’s wet season from April to December, and reproductively quiescent during the dry season. Lytechinus variegatus, Tripneustes ventricosus, and Clypeaster subdepressus are ripe throughout the year, while Echinometra lucunter shows non-periodic fluctuations in readiness to spawn. The data do not support the hypothesis (Lessios 1981) that in constant environments rare species should exhibit greater reproductive synchrony than common species.
